The Present Disclosure relates generally to structures used in and associated with electronic modules for reducing electromagnetic interference (EMI) radiation therefrom, and more particularly to a cost-effective shielding member for use with a shielding cage which houses a connector on a printed circuit board and receives an electronic module therein, for mating to the connector.
Electronic modules are used to connect various electronic devices together. Such modules are usually terminated to opposing ends of a cable to define a cable assembly that is used to interconnect a server to a router, for example. Such modules may incorporate fiber optic, electrical or combined transceivers that are formed in the shape of a plug. Such plugs are received within receptacles that are disposed within electrical equipment. These receptacles can include metal or die cast guide frames or sheet metal or metalized cages to form a conductive receptacle. Such a receptacle commonly includes opposing top and bottom walls, opposing side walls joining the top and bottom walls together to define a four walled enclosure. A rear wall typically interconnects the side walls and top walls together with an opening formed in the bottom wall so that the receptacle can be mounted to a circuit board over a connector, which is also mounted to the circuit board.
These modules are often constructed in accordance with various standards that dictate the size and compatibility so that modules can be used interchangeably within a standard. These standards are now envisioning data transfer rates of 25 gigabytes per second (GBPS) and upwards of 100 GBPS or greater.
At such high data transfer speeds, the modules generate electromagnetic energy. As the amount of such energy increases, the energy may pass through gaps in the receptacle to an extent that it causes EMI that can adversely affect the transmission of data signals through the module, and the adjacent modules associated electronic equipment to which it is connected. It is therefore desirable to shield data signals from EMI to the entire extent of the receptacle.
In most cage-style receptacles having a lower opening, gaskets are provided along a portion of the perimeter opening. For example, U.S. Pat. No. 6,752,663 discloses the use of a conductive foam gasket that extends along three sides of the receptacle bottom opening. A separate metal spring is positioned along the fourth side of the opening. Extending the foam gasket to cover the fourth side of the spring is impractical and it may lead to poor mounting of the receptacle on the circuit board. Thus the need for the metal spring gasket along the fourth side. This type of multiple-piece assembly is costly costing approximately more than a dollar to manufacture. There is additional cost associated with applying the gasket to the receptacle. It is therefore desirable to provide an inexpensive member to a receptacle for purposes of providing EMI shielding to the receptacle.